test: preserve grok video resolution forwarding

backend/internal/service/openai_gateway_grok_test.go

@@ -365,7 +365,7 @@ func TestForwardGrokMediaVideoGenerationReturnsUsageAndResponseID(t *testing.T)
 	result, err := svc.ForwardGrokMedia(context.Background(), c, account, GrokMediaEndpointVideosGenerations, "", body, "application/json")
 	require.NoError(t, err)
 	require.Equal(t, "https://xai.test/v1/videos/generations", upstream.lastReq.URL.String())
-	require.JSONEq(t, `{"model":"grok-imagine-video","prompt":"waves"}`, string(upstream.lastBody))
+	require.JSONEq(t, `{"model":"grok-imagine-video","prompt":"waves","resolution":"720p"}`, string(upstream.lastBody))
 	require.Equal(t, "video-request-123", result.ResponseID)
 	require.Equal(t, "grok-imagine-video", result.BillingModel)
 	require.Equal(t, 3, result.Usage.InputTokens)